Lubricant



Patented Mar. 14, 1950 UNITED PATENT ore-ice LUBRICANT Orland Rein and Harry J. Andress, Jr.,Woodbu y, 5., assignors to Socony-Vacuum Oil Company, Incorporated, a corporation of New York No Drawing. Application J 1115' 11, 1946, Serial N 682.929

oil. These deposits accumulate about the piston rings, causing them to stick. There is also developed in the Oi as the result of oxidation, appreciable acidity which has a deleterious effect upon metal parts with which the oil comesin contact. This is particularly severe in the case of certain types of alloy-bearing metals, such as copper-lead, cadmium-nickel, cadmium-silver, and the like. Additionally, the lubricating effectiveness of such lubricant compositions may be seriously reduced by virtue of the relatively large change in viscosity at engine operating temperatures.

We have now discovered that the foregoing shortcomings of lubricant compositions may be overcome substantially by the incorporation therein of small amounts two characterizing agents which cooperate to provide a syne stic effect, rather than a mere additive effect. The. characterizing agents which have this surprisa ing cooperative action are oil-soluble. PhOfiPhQrus-v containing compounds and oil-soluble compounds characterized by a thiophene nucleus.

The oil-soluble, phosphorusecon'taining com-.- pounds contemplated herein include the, phos phites, phosphates, thiophosphites, thiophosphates, and their corresponding metal, am;- monium, and amine salts; phosphines; reaction products of phosphorus-containing reagents, such as phosphorus oxides, sulfides, halides, oxyand thio-halides with various organic materials such as olefins, terpenes, alcohols, esters, ketones, acids, amines, etc.; phosphatides' such aslecithin, cephalin, etc.; organo heterocyclic compounds containing phosphorus in the heterocyclic ring.

The typical phosphorus-containing characterizing agents are:

(1) Phosphites Amyl phenyl phosphlte Dibutyl phenyl phosphlte Triwax phenyl phosplnte (2) Phosphates Tricresyl phosphate Lauryl phenyl phosphate Triwaxphen-yl phosphate (3) Thiophcsphites Dibutyl thiophosphlte Tri xylenyl thiophosphite Triwax phenyl thiophosphlte Thiophospllates Tricresyl thiophosphate Tri xylenyl thioph'osphate Triwax phenyl thlophosphato 2 Claims. (Cl. 2529463) i l aralkyl groups.

(5) Phosphines D butyl phenyl phosphlne D uryl p e l m r hin Dlwax p e yl phosph ne (6) Phosphorus-containing reaction products of:

(a) hos phorus 0 11 3 2 a, ,5 (b) Phosphorus sulfides P1 3, Pi Pi a, 13$

(0) Phosphorus halides P613, P015, PBr P001 P801;

n a m ter 9 Q5 i1 fo l win Olefms utylene, amylene, para-flin WB lefin Terpenes e. a p iene. t rpen ne l Alcohols octyl, decyl, lauryl, cetyl Ketones dphorone, dioleyl ketone 01 siearic, oleic, salicylic Amines a y stee -Y1,v anil ne (7) Phosphorus-containing natural products lecithin, cephaliu The characterizing agent which cooperates with the aforesaid oil-soluble. phosphorus-containing compounds is an oil-soluble compound characterized by a thiophene nucleus. This class of materials is inclusive of alkylesubstituted thins phenes, their corresponding sulfide, oxide, selenide, sulfonate, sulfonamide and nitro derivatives. For example, the alkyl-substituted thiophenes may be represented by the general formula:

R3C-CR* wherein R R R and R are selected from the group consisting of hydrogen and substituted and unsubstituted 1 alkyl, alkaryl, aryl, and The latter groups, as indicated, may carry one or more substituents such as sulfur, chlorine, hydroxy, nitro, sulfate, etc. It will be clear that at least one of the aforesaid R groups in the foregoing general formula will be an alkyl group such, for example, as butyl, amyl, octadecyl, paraffin wax, or the-like, The sulfides, oxides, and selenide derivatives of the alkyl-substituted thiophenes will, ofcourse, contain a sulfide, oxide or selenide bridge linking two or more thiophene nuclei. Typical of such materials is, diamyl thiophene sulfide.

Illustrative of the preparation of typical thicphene compounds contemplated. herein are those described in the following examples.

Paramn wax-substituted dflz'butyli-thiophene A mi ture consistin of 1 0 grams o dibu ylthiophene, 260 grams of chlorinated paraflin wax containing 14 per cent by weightof. chlorine (the paraffin wax has a molecular weight at about 359 and a melting point of about. 126?" E.) and 3" per cent by weight. of anhydrous: aluminum chloride, was heated to a. temperature ciiabout 3509 in 150-200 F., and an amount ofwater equal to.

about one-quarter the volume of the reaction mixture was added. About 3 per cent by weight of zinc dust was then added and the resulting reaction mixture was stirred for about 30 minutes. During this latter treatment, the reaction mixture was decolorizedjand the aluminum chloride therein was dissolved in the water layer which separated, the water layerwas then removed and the remaining reaction mixture was washed with several portions of water. Butanol was used in conjunction with the water to break emulsions which formed. The water-washed reaction mixture was heated to remove the butanol and any residual water. The product thus obtained was predominantly parafiin wax-substituted dibutylthiophene and was characterized by EXAMPLE II Pamflin war-substituted thiophene A parafl'in wax having a melting point of about 126 F., a molecular Weight of about 350, and containing at least 20 carbonatoms withan average I of 24 carbon. atoms, was chlorinated by bubbling chlorine therethrough until the weight of the wax had increased by about 13 per cent. Two hundred 'cants.

about 460 F. to remove any unreacted thiophene. The reaction product is predominantly monopa'rafiin wax thiophene and is characterized by the following: A. P. I. gravity 25.8; viscosity index 137.0; 6.26 per cent sulfur; molecular weight of 456 and a pour point of 80 F.

It will be noted that the pour points of the products obtained in'Examples I and 11 above are relatively high. These materials contain some free parafiin wax "and can be dewaxed by the usual methods for dewaxing mineral oil lubri- The dewaxed materials, those from which substantially all free parafiin wax has been removed, have sufiiciently low pour points to be used as synthetic oils. For example, the monoparaflin wax thiophene prepared in Example II above was dewaxed by diluting the same with 600 per cent by weight of methyl ethyl ketone followed by cooling the resulting mixture to 0 F.

and filtering thecooled mixture at 0 F. The filtrate thus obtained was distilled to remove the methyl ethyl ketone and to obtain a product substantially free of paraffin wax. The monoparafiin wax thiophene thus obtained had a pour point of +20 F.

The synergistic effect of the aforesaid phosphorus-containing and thiophene type characterizing agents is demonstrated by the Lauson engine test; data presentedin Table 1 below. The Lauson engine test is anoperation test and involves operating a singlecylinder Lauson engine for 36 hours at an oil temperature of 290 F. and a jacket temperature of 212 F. The oil used is a solvent-refined oil having a kinematic viscosity of 5.8 centistokes. (S. U. V. of 45 seconds at 210 F.) After 36 hours of test, the acidity as represented by the neutralization number (N. N.) of the oil blend is measured.

Table 1 Gone. 1 Per Cent Test Characterizing Agent W t. N. N. Improve- PIS Ratio No. Added Percent ,4 ment 14.6 Dibutyl thiophene- 0. 4 13. 5'

8. 4 Amylphenyl-phosp 0. 43 5.1

one; 11.4 Dibutylthiophene 4 0. 6

Amylphenyl phosphita.

N one Dibutyl thiophene. Amylphenyl phosp None Dibutyl thiophene 0. Amylphenyl phosphite. -0

grams of the chlorinated paraffin wax so prepared was contacted with 45 grams of lime Ca O) and the resultant mixture was agitated and heated for about 5.hours at about 500 F. Hydrogen chloride was evolvedduring this treatment and was neutralized, to a large extent, by reaction with the lime thus forming CaClz. The reaction mixture was filtered to remove the 'CaO-CaCh mixture and to obtain the unsaturated paraiiin wax or parafiin wax olefin. "The iodine value of the parafin wax olefin Wasabout 100.

A mixture of 100grams of the aforesaid paratfin wax olefin and 30 grams of thiophene was heated in an autoclave at about 400- F. for about 5 hours in the presence of about 10 per cent by H weight offa synthetic clay catalyst. The catalyst comprises silica in association with alumina. The reaction mixture was cooled and filtered toremove' the clay catalyst. The filtrate thus obtained was distilled to a maximum temperature of It will be clear from the foregoing tabulation that the combination of dibutylthiophene and amylphenylphosphite is more than a mere additive combination, inasmuch as the degree of improvement to be expected from this combination is only of the order of 46 per cent as indicated by an oil blendcontaining the dibutylthiophene alone and an oil blend containing the amylphenylphosphite alone. The corresponding oil blend containing both materials in the same concentrations provides an improvement of 94.7 per cent. It is also evident from the foregoing test results that the relative concentrations of thiophene compound and phosphorus compound influences the degree of synergistic action. This relationship is expressed in terms of the phosphorus to sulfur ratio of the compounds used in the oil. 'With the foregoing combination of amylphenylphosphite and dibutylthiophene, it has been found that the optimum phosphorus to sulfur ratio is of the order of 0.4 and it is preferred that this ratio be maintained between about 0.1 and 0.8.

Not only may the phosphorus-containing agent and the thiophene agent be incorporated singly in the oil, but they may also be reacted together prior to the incorporation in the oil. In either case, the efiect is not an additive one but a synergistic efiect.

The oil-soluble phosphorus-containing compounds are generally used in the oil in concentrations of the order of about 0.4 per cent to about 1 per cent and the thiophene type compounds may be used in amounts from about 0.2 per cent to about 1 per cent, with the relative concentrations being so proportioned that the preferred phosphorus to sulfur ratio discussed above is maintained. These characterizing agents may be used in viscous mineral oils, volatilized oils, synthetic oils, greases and fatty oils, such as corn oil, soybean oil, lard oil, and the like. It should be clear that these characterizing materials may also be blended, that is, used as blending agents, in oils of the aforesaid type in higher concentrations than those enumerated above. They may, for example, predominate in the blend. In addition, the phosphorus-containing materials and thiophene nuclear materials, contemplated herein, may also be used as synthetic lubricants free from oils such as recited above, in view of their unusual lubricating value.

It is to be understood that the present invention is not to be construed as limited to the foregoing illustrative examples but is to be construed broadly in the light of the language of the appended claims.

We claim:

1. A mineral oil composition comprising a major proportion of a viscous mineral oil fraction, a minor proportion, from about 0.4 per cent to about 1 per cent, of amyl phenyl phosphite and a minor proportion, from about 0.2 per cent to about 1 per cent, of dibutyl thiophene.

2. A mineral oil composition comprising a major proportion of a viscous mineral oil fraction, a minor proportion, from about 0.4 per cent to about 1 per cent, of an alkyl phenyl phosphite and a minor proportion, from about 0.2 per cent to about 1 per cent, of a lower alkyl-substituted thiophene.

ORLAND M. REIFF. HARRY J. ANDRESS, JR.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 2,160,293 Shoemaker et al. May 30, 1939 2,258,806 Pier et a1 Oct. 14, 1941 2,315,072 Nelson et a1 Mar. 30, 1943 2,413,353 Hunter Dec. 31, 1946 

2. A MINERAL OIL COMPOSITION COMPRISING A MAJOR PROPORTION OF A VISCOUS MINERAL OIL FRACTION, A MINOR PROPORTION, FROM ABOUT 0.4 PER CENT TO ABOUT 1 PER CENT, OF AN ALKYL PHENYL PHOSPHITE AND A MINOR PROPORTION, FROM ABOUT 0.2 PER CENT TO ABOUT 1 PER CENT, OF A LOWER ALKYL-SUBSTITUTED THIOPHENE. 